Engine/world from config (#882)

* feat: clean `from::engine` interface

arbiter-engine/src/examples/minter/config.toml

@@ -1,3 +1,6 @@
+# id for the world
+id = "minter_world"
+
 # top level id for the `TokenAdmin` agent
 [[admin]]
 # named struct and arguments for initializing the `TokenAdmin` agent

arbiter-engine/src/examples/minter/mod.rs

@@ -86,8 +86,7 @@ enum Behaviors {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn config_test() {
-    let mut world = World::new("world");
-    world.from_config::<Behaviors>("src/examples/minter/config.toml");
-
+    let mut world = World::from_config::<Behaviors>("src/examples/minter/config.toml").unwrap();
+    assert_eq!(world.id, "minter_world");
     world.run().await;
 }

arbiter-engine/src/examples/timed_message/config.toml

@@ -1,3 +1,5 @@
+id = "timed_message_world"
+
 [[ping]]
 TimedMessage = { delay = 1, send_data = "ping", receive_data = "pong", startup_message = "ping" }
 

arbiter-engine/src/examples/timed_message/mod.rs

@@ -203,8 +203,8 @@ enum Behaviors {
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn config_test() {
-    let mut world = World::new("world");
-    world.from_config::<Behaviors>("src/examples/timed_message/config.toml");
-
+    let mut world =
+        World::from_config::<Behaviors>("src/examples/timed_message/config.toml").unwrap();
+    assert_eq!(world.id, "timed_message_world");
     world.run().await;
 }

arbiter-engine/src/world.rs

@@ -98,9 +98,8 @@ impl World {
     /// BehaviorTypeC = { ... }
     /// ```
     pub fn from_config<C: CreateStateMachine + Serialize + DeserializeOwned + Debug>(
-        &mut self,
         config_path: &str,
-    ) -> Result<(), ArbiterEngineError> {
+    ) -> Result<Self, ArbiterEngineError> {
         let cwd = std::env::current_dir()?;
         let path = cwd.join(config_path);
         info!("Reading from path: {:?}", path);
@@ -109,17 +108,26 @@ impl World {
         let mut contents = String::new();
         file.read_to_string(&mut contents)?;
 
-        let agents_map: HashMap<String, Vec<C>> = toml::from_str(&contents)?;
+        #[derive(Deserialize)]
+        struct Config<C> {
+            id: Option<String>,
+            #[serde(flatten)]
+            agents_map: HashMap<String, Vec<C>>,
+        }
+
+        let config: Config<C> = toml::from_str(&contents)?;
 
-        for (agent, behaviors) in agents_map {
+        let mut world = World::new(&config.id.unwrap_or_else(|| "world".to_owned()));
+
+        for (agent, behaviors) in config.agents_map {
             let mut next_agent = Agent::builder(&agent);
             for behavior in behaviors {
                 let engine = behavior.create_state_machine();
                 next_agent = next_agent.with_engine(engine);
             }
-            self.add_agent(next_agent);
+            world.add_agent(next_agent);
         }
-        Ok(())
+        Ok(world)
     }
 
     /// Adds an agent, constructed from the provided `AgentBuilder`, to the

arbiter-macros/src/lib.rs

@@ -158,8 +158,7 @@ pub fn main(attr: TokenStream, item: TokenStream) -> TokenStream {
             match &args.command {
                 Some(Commands::Simulate { config_path }) => {
                     println!("Simulating configuration: {}", config_path);
-                    let mut world = World::new("world");
-                    world.from_config::<#behaviors>(config_path);
+                    let mut world = World::from_config::<#behaviors>(config_path)?;
                     world.run().await?;
                 },
                 None => {